The invention relates to a method for preparing a flour tortilla (including whole wheat, multi grain), to a tortilla obtainable by such a method and to the use of a fatty substance to improve a property of a tortilla prepared using a fatty substance.
Flour tortillas are a unique baked product, made from cereal flour, usually maize or wheat.
Wheat flour tortillas are gluten structured, just like bread. Almost all tortillas are chemically leavened, baked quickly and cooled to ambient temperatures in less than 15 minutes.
Flour tortillas have soft, silky, smooth texture, are opaque and fluffy and have excellent pliability; are resistant to cracking and have small, evenly distributed blisters. Blisters create desirable characteristics in the final product, showing up as lightly browned spots on the surface.
Flour tortillas are becoming increasing popular, for instance as a substitute for bread, rolls and buns.
Flour tortillas can be made by making a dough from flour, fat and salt and water. Most large commercial tortilla manufacturers use the hot-press method of mixing, forming and baking to produce flour tortillas, e.g. as described in Bello, A. B.; Serna-Saldivar, S. O.; Waniska, R. D. and Rooney, L. W. Methods to prepare and evaluate wheat tortillas, Cereal Foods World (1991)
In this method, a smooth dough comprising flour, water, fat, salt, and usually one or more ingredients selected from baking powder, yeast, preservatives, gums, reducing agents and emulsifiers is mixed to an extensible, elastic, non-sticky and relatively firm dough.
By optimally mixing and adding proper water levels a silky, smooth-textured dough, with many layers in the final product is formed.
Dough temperature also affects consistency, with lower dough temperatures increasing water absorption. This leads to a softer final product. The temperature may for instance be in the range of 27-38° C. The optimum temperature for flour-tortilla dough is usually 27° to 33.5° C.
After mixing, the tortilla dough is scaled to a desired weight, usually from about 30 to about 150 gram, e.g. about 40 to about 50 gram or about 45 to about 48 gram, depending on the desired diameter for the tortilla, is rounded into a ball and is then allowed to rest (relax, proof, usually for about 5-15 minutes. Proofing the dough helps the pressing process. Insufficient relaxation can result in a translucent finished product with less layering.
After resting, the dough pieces are placed under a hydraulic press that is heated. The pressing process forms a thin skin on the surface of the tortilla, limiting the escape of steam and carbon dioxide during baking. This causes the tortilla initially to form small blisters or gas pockets which deflate upon cooling.
Baking is usually done in a conveyer oven that flips the tortilla over during its journey through the oven. In particular, a specialized direct gas fired slatted belt may be used. Baking time (oven dwell time) may for instance be approximately 30 seconds in a 190° to 235° C. oven. In a specific embodiment, the oven temperature is 190-200° C. The tortillas are then cooled and packaged.
The over-all quality of tortillas, is determined by various properties. In particular tortillas having a reduced fat content may be considered inferior to regular-fat tortillas (typically containing about 8-12 wt. % fat, for instance 8-9 wt. % fat), but also for regular-fat tortillas it is desirable to improve one or more properties.
Relevant properties in particular include:
Folding: a low tendency to break on the seams upon folding the tortilla is desired.
Breaking: it is desired that the tortilla shows good resistance against tearing. E.g. low-fat tortillas tend to be torn apart at a lower tearing force than regular tortillas.
Rolling: a good tortilla should be easily rollable, e.g. around a known diameter dowel, rod or stick, without showing substantial cracking and/or breaking. This is especially a challenge upon aging of the tortillas. Thus, it would be desirable to provide a tortilla that has good rolling properties. In particular it is desired to provide a tortilla with good rolling properties for a prolonged period of time.
Springiness: Upon taking a low fat full tortilla in one hand and crumpling or wadding it firmly, it is desirable that the tortilla ‘springs back’ freely and unfolds completely without breaking.
Colour: a product with a substantially uniform (off-)white colour, wherein blisters are present is appreciated by many consumers. The blisters show up as lightly browned spots on the surface. In particular, low-fat tortillas have a less off-white, more pale and less uniform colour.
Layering/lamination: a layered structure of the tortilla is desired. In particular, low-fat tortillas tend to be less layered compared to regular tortillas.
Dryness: a tortilla should preferably have a not too dry mouthfeel Consumers recognize reduced fat and low fat tortillas as having a drier mouthfeel than traditional full fat tortillas.
Size: The size (diameter) of conventional reduced fat tortillas is significantly smaller than the size of regular-fat tortillas, of the same weight. Low-fat tortillas of a specific weight may for instance have a diameter that is less than 90% of the diameter of a regular-fat tortilla of the same weight and apart from the fat having the same composition
Uniformity size/shape: Reduced fat tortillas tend to be less uniform in shape and size.
Stacking stickiness: It is desired that—when stacked and packaged—tortillas show no or a low tendency to stick to one another. In particular, upon aging the tendency to stick may increase. In particular, tortillas known in the art, made with vegetable oil instead of solid shortening tend to stick more to each other upon prolonged shelf life. Also tortillas, known in the art, made with enzymes, such as bacterial or fungal amylases, tend to stick more to each other, regardless of shelf life.
Stack height: As a consequence of smaller diameters, the height of a stack of, e.g., 10 tortillas is generally higher for reduced fat tortillas than for regular fat tortillas; i.e. low fat tortillas are thicker than regular tortillas. This is unwanted due to negative effects on rollability, foldability and eating characteristics.
Opacity: Opacity is measured subjectively using a continuous scale. 100% is completely opaque (white) and 0% is completely translucent (not white). Ideally, translucency is eliminated since opacity is a desired quality attribute.
It is an objective of the present invention to provide a novel method for preparing a flour tortilla, respectively a novel flour tortilla, wherein one or more of the above properties are improved compared to a tortilla having the same composition, prepared with a known hot-press method, such as described above.
It is in particular an objective of the invention to provide a novel method for preparing a flour tortilla, respectively a novel flour tortilla with a reduced-fat content, in particular with a fat content of less than 5 wt. %. In a particularly preferred embodiment, the fat content is less than 4 wt. %, less than 3 wt. %, less than 2 wt. %, less than 1 wt. % or less, close to 0 wt. %, having one or more improved properties, compared to a known flour tortilla having the same fat content.
One or more other objectives which may be met in accordance with the invention will be apparent from the description, below.